How to test fuel pump?

[gavinl]

I think my fuel pump is dead. I checked for 12v at the fuse box and connector to the fuel pump and they were ok (got 11v).

Is there an electrical way to test the fuel pump (i.e. impedence, continuity,etc?) beside putting an external 12v on the fuel pump connection?

 

[sbc350gearhead]

You can test voltage at the fuel pump, or you car turn the key to the on position, and you will hear the pump kick on and prime the system.

 

[JohnBrowning]

CHeck the pressure at the rail and then check for flow rate. What year make and model is this? If it is a 96 or newer GM vechile you can use the Tec-2 see gameboy to check it as well.

 

[gavinl]

Sorry, forgot to mention it's a 94 Ford T-bird 4.6.

On a few occassions I hear the fuel pump prime but with knocking sounds, then dead silence from the pump....just sounds of the relay clicking.

Gonna get myself a fuel pressure tester to double check the flow at the rails.

I really don't want to drop the exhaust and fuel tank in this cold crappy Ohio weather.....(not heated garage)

 

[Ken4]

What's the lifespan of an in-tank fuel pump? I've heard it said that the average is only 4 years.

 

[Robbie Alexander]

quote:

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Originally posted by Ken4:
What's the lifespan of an in-tank fuel pump? I've heard it said that the average is only 4 years.

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I like to know.
Mine may be on the way out again.
My first one on this toyota went out (gotta check the records, maybe 250-280K maybe 300K - gotta find the numbers). anyway it may be on the way again at 392K
My brother in law
his GM trucks go every 100K
I know others that go every 150-200 K

I have had trucks that went over 5-6-800 K and never went out... most my cars it has never went out, but most my cars I only put a few hundred (1-2-3-4) K... just depends.

What I'd like to do if it is possible, is put an extra one (INLINE) and only turn it on if I need it... if theres any guru that knows how this can be done, I'd like to do that...

 

[ZR2RANDO]

I think that fuel pump life sometimes is dictated by fuel conditions in the tank, rather than just a normal pump life expectancy. Sometimes you get a couple tanks of gas that have some crud/dirt/water (fine powder clay from filters in bulk tanks..). The gradual buildup of debris in the tank eventually clogs the pump intake screen and then the pump overheats and finally works itself to death. When you replace the pump make sure you clean out the tank properly so the new pump has its best chance for long term service.
If you notice your fuel filter clogs quicker than it should, the pump intake screen is probably also clogging up as well....

 

[Kestas]

You may want to check the relay first. Though it's clicking, the contacts could be burnt, thus not putting out 12v to the pump.

 

[gavinl]

Well my t-bird has 138k on the tick and the fuel tank is plastic.

The relay is built into the engine control module so cannot be replaced. I did check for 12v to the fuel pump connector and it was good.

I guess I'm down to cutting the exhaust pipe to drop the fuel tank

 

[JohnBrowning]

You are jokeing right!!! Only a moron would make a fuel pump relay non-serviable. Check the main power junction box their should be a relay for fuel pump. Most fuel pump relays are either the 1/2 inch cube style or the old school snack size snicker bar sized ones like typical Bosch relay. If Ford put the relay in the ECM I would fix the vechile and sell it. You do not have to put up with this type of moronic design!

 

[gavinl]

No kidding, the fuel pump relay is built into a secondary "ECM" which Ford calls a IRCM.

There's is a fuse that is in the fuel pump circuit and I tested that already, it's good.